Cause1: The sensor cable is not connected, or almost disconnected.
Action1: Connect the sensor cable securely.
Cause2: The elongation meter is improperly mounted.
Action2: Mount the elongation meter securely.
Cause3: The sensor is incompatible with the transducer amplifier.
Action3: Connect the sensor to the compatible type of transducer amplifier, and restart the controller.
Cause4: The CAL cable is incompatible with the sensor.
Action4: Connect the sensor with the compatible type of CAL cable, and restart the controller.